An Artificial Heart as a Bridge to Heart Transplantation

An Artificial Heart as a Bridge to Heart Transplantation

In heart failure, the heart is weaker than normal and cannot pump enough blood throughout the body. Blood moves through the heart and body at a slower rate, causing the pressure in the heart to increase. The walls of the heart expand to hold more blood, but this is only a temporary solution. Eventually, the heart muscle weakens and excess fluid backs up into the lungs and other parts of the body. This is known as
congestive heart failure (CHF)
.

It is estimated that 5 million people in the US have heart failure and about 300,000 die from it each year. It is normally managed through medication and lifestyle changes such as eating healthfully. When CHF becomes severe, a
heart transplant
may be the last resort for a patient who can still tolerate surgery.

In 2002, 2,154 heart transplants were performed in the US. But, it is estimated that 30,000 to 70,000 Americans could benefit from a heart transplant, and 15 to 25% of the Americans who die each year of heart failure died waiting for a new heart. Unfortunately, while the demand for donor hearts has doubled in recent years, the supply of donor hearts has decreased.

A study published in the August 26, 2004 issue of the
New England Journal of Medicine
looked at the use of an artificial heart, temporarily implanted, as a bridge to cardiac transplantation in patients with heart failure.

About the study

The study looked at 81 patients with end-stage congestive heart failure who received the CardioWest Total Artificial Heart while awaiting a heart transplantation. The CardioWest Artificial Heart is a blood pump that completely replaces the heart’s ventricles—the two lower chambers of the heart. At maximum cardiac output, the artificial heart can pump 9 liters of blood per minute.

The 81 patients who received the artificial-heart device were compared to 35 patients in the control group who had been waiting for a heart transplant but never received an artificial heart.

When the researchers compared the two groups, they looked at:

Rates of survival to transplantation

Overall survival rate at one and five years after transplantation

Treatment success (30 days after transplantation, patient was alive, walking around, and not dependent on a ventilator to breath or dialysis for kidney function)

The findings

The researchers found that the patients who received the artificial heart as a bridge to heart transplantation had significantly better outcomes when compared to the patients who had not receive the artificial heart. Specifically, 79% of patients with the artificial heart survived to their scheduled heart transplantation compared to only 46% of the patients who did not have the artificial heart. Interestingly, the average time from entry into the study and heart transplantation was almost 80 days in the patients with the implant, but less than 9 days for the control group.

The survival rates are listed in the following table:

Survival Rate

Treatment group (with artificial heart)

Control Group(without artificial heart)

Overall

70%

31%

One-year after transplantation

86%

69%

Five-years after transplantation

64%

34%

Additionally, 69% of patients with the artificial heart achieved treatment success as compared to 37% of the control group.

The study’s authors note that the quality of life among the patients who received the implant was significantly improved—citing that 75% of these patients were able to get out of bed one week after the procedure.

How does this affect you?

Heart failure claims 300,000 lives in the US alone and 45,000 to 75,000 die while waiting for cardiac transplantation. This study found that implantation of the CardioWest Total Artificial Heart as bridge to a new heart significantly increased survival and improve the quality of life for dying patients. This is just one successful example of a growing technological trend, which seeks to replace diseased organs and tissues with artificial devises.

While this is encouraging news for congestive heart failure patients and their families, an artificial heart, even a temporary one, is extremely expensive to build, implant and maintain. Until the price of this technology comes down, it will remain out of reach for most patients dying for a new heart.

Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a
medical condition.